Encapsulation film

ABSTRACT

Provided are an encapsulating film, an electronic device and a method of manufacturing the same. An encapsulating film having excellent moisture blocking property, handleability, workability and durability and a structure including a diode encapsulated with the encapsulating film may be provided.

This application is a bypass continuation of International ApplicationNo. PCT/KR2013/000108, filed Jan. 7, 2013, which claims priority toKorean Patent Application Nos. 10-2012-0002170, filed on Jan. 6, 2012and 10-2013-0001833, filed on Jan. 7, 2013, in the Korean IntellectualProperty Office, all of which are incorporated herein by reference.

The present application relates to copending application Ser. No.14/244,693, filed on Apr. 3, 2014; Ser. No. 14/323,703, filed on Jul. 3,2014; and Ser. No. 14/323,827, filed on Jul. 3, 2014.

BACKGROUND

1. Field of the Invention

The present invention relates to an encapsulating film, an electronicdevice and a method of manufacturing the same.

2. Discussion of Related Art

An encapsulating film may be used to protect a diode or device sensitiveto an external factor such as moisture or oxygen. In the diode or devicewhich can be protected by the encapsulating film, for example, anorganic electronic device, a solar cell or a secondary battery such as alithium secondary battery may be included. Particularly, among thediodes or devices, the organic electronic device is vulnerable to anexternal factor such as moisture or oxygen.

The organic electronic device is a device including a functional organicmaterial. As the organic electronic device or an organic electronicdiode included in the organic electronic device, a photovoltaic device,a rectifier, a transmitter or an organic light emitting diode (OLED) maybe used.

The organic electronic device is generally vulnerable to an externalfactor such as moisture. For example, the OLED usually includes a layerof a functional organic material present between a pair of electrodesincluding a metal or metal oxide, and the layer of an organic materialis detached due to an effect of moisture penetrating from an externalenvironment at an interface with the electrode, is increased inresistance value due to oxidation of an electrode by moisture, or isdegenerated, thereby causing problems such as a loss of an emissivefunction or a decrease in luminescence. Accordingly, to protect the OLEDfrom a factor of an external environment such as moisture, anencapsulating structure formed by covering the OLED formed on asubstrate with a glass can or metal can equipped with a getter or amoisture absorbent and fixing the resulting OLED with an adhesive isused.

SUMMARY OF THE INVENTION

The present invention is directed to providing an encapsulating film, anelectronic device and a method of manufacturing the same.

One aspect of the present invention provides an encapsulating filmincluding a first layer and a second layer. The encapsulating film mayinclude at least one of each of the first and second layers, and furtherinclude an additional layer in addition to the first and second layers.

The encapsulating film includes first and second layers having differentphysical properties and/or components. The film may be laminated on adiode without bubbles even when applied to a large-scale device toprotect the diode, and effectively protect the diode from an externalfactor, for example, moisture, after encapsulation. The encapsulatingfilm may have various structures such as a structure in which a secondlayer 11 is disposed on one surface of a first layer 12 as shown in FIG.1, or a structure in which second layers 11 are disposed on bothsurfaces of a first layer 12 as shown in FIG. 2. Here, the structure inwhich the second layer 11 is disposed on one or both surfaces of thefirst layer 12 may include a structure in which the second layer 11 isdirectly attached to the first layer 12, and a structure in which thesecond layer 11 is indirectly attached to the first layer 12 via anotheradditional layer.

In the encapsulating film, the first layer may have a lower elasticmodulus than the second layer. For example, the tensile modulus of thefirst layer may be lower than that of the second layer. Unlessparticularly defined otherwise, the tensile modulus used herein ismeasured at 25° C. In addition, the tensile modulus with respect to acurable component used herein is, unless particularly defined otherwise,a tensile modulus measured after curing.

When the elastic modulus of the first layer is lower than that of thesecond layer, the encapsulating film is preferable to be applied to alarge-scale device, and an effective moisture blocking property can beprovided to the film as result of controlling a ratio of a moisturescavenger between the first and second layers. The term “moisturescavenger” used herein may refer to a material capable of removingmoisture or vapor penetrating the encapsulating film through a chemicalreaction with the water or vapor. Usually, when the moisture scavengeris reacted with moisture in the film, a volume expands to the extent ofthe reaction with moisture, thereby generating a stress. Accordingly, ifthe tensile modulus is not sufficient to reduce an expansion stressgenerated during the removal of moisture, the film may be detached froman adherent or induce inter-layer detachment in the case of a multilayerstructure. For example, when the elastic modulus of the film iscontrolled to decrease, the detachment due to the stress may beprevented. However, when the elastic modulus is controlled by reducing aglass transition temperature through simply controlling a curing degree,a water vapor transmission rate (WVTR) of the film may be increased.However, when two layers having different elastic moduli are stacked anda moisture scavenger is mainly included in the layer having a lowerelastic modulus of the two layers as described above, moisturepenetrating through the layer having a relatively smaller amount of themoisture scavenger, that is, the layer having a higher elastic modulus,may be diffused to the layer having a lower elastic modulus, therebyenhancing a moisture blocking property. In addition, other physicalproperties such as durability of the film may also be satisfied. In oneexample, the tensile modulus of the first layer may be approximately0.001 to 400 Mpa, 0.001 to 300 Mpa, 0.001 to 200 Mpa, 0.001 to 100 Mpa,0.001 to 80 Mpa, 0.001 to 60 Mpa, 0.001 to 40 Mpa, 0.001 to 20 Mpa,0.001 to 10 Mpa, 0.001 to 5 Mpa, 0.001 to 3 Mpa, 0.001 to 1 Mpa, 0.005to 100 Mpa, 0.01 to 100 Mpa, 0.05 to 100 Mpa, 0.1 to 100 Mpa, 0.2 to 100Mpa, 0.3 to 100 Mpa, 0.005 to 80 Mpa, 0.01 to 60 Mpa, 0.05 to 40 Mpa,0.05 to 20 Mpa, 0.1 to 10 Mpa, 0.1 to 5 Mpa, 0.2 to 3 Mpa or 0.3 to 1Mpa. In addition, the tensile modulus of the second layer may beapproximately 400 to 1000 Mpa, 400 to 900 Mpa, 400 to 800 Mpa, 400 to700 Mpa, 400 to 1000 Mpa, 500 to 1000 Mpa, 550 to 1000 Mpa, 400 to 900Mpa, 500 to 800 Mpa or 550 to 700 Mpa. In the above range, the firstlayer may have a lower elastic modulus than the second layer. Forexample, a ratio (M1/M2) of the tensile modulus (M1) of the first layerto the tensile modulus (M2) of the second layer may be approximately1×10⁻⁶ to 0.5, 1×10⁻⁶ to 0.4, 1×10⁻⁶ to 0.3, 1×10⁻⁶ to 0.2, 10×10⁻⁶ to0.5, 100×10⁻⁶ to 0.5, 200×10⁻⁶ to 0.5, 300×10⁻⁶ to 0.5, 400×10⁻⁶ to 0.5,500×10⁻⁶ to 0.5, 10×10⁻⁶ to 0.4, 100×10⁻⁶ to 0.4, 200×10⁻⁶ to 0.3,300×10⁻⁶ to 0.3, 400×10⁻⁶ to 0.2 or 500×10⁻⁶ to 0.2. In the relationshipof the elastic modulus described above, the encapsulating film may alsobe effectively applied to a large-scale device, and easily controlled ina ratio of the moisture scavenger between the layers, which ispreferable to control physical properties of the film.

In one example, the encapsulating layer may include a moisturescavenger. In this case, the first layer may include a larger amount ofmoisture scavenger than the second layer. The second layer may include asmaller amount of the moisture scavenger than the first layer, or maynot include the moisture scavenger. As will be described later, in theabove structure, for example, when the second layer has an encapsulatingstructure is realized such that the second layer is in contact with adiode, the diode may not be damaged, and an excellent moisture or vaporblocking property may be exhibited. For example, the first layer mayinclude a resin component and a moisture scavenger at 5, 10, 20, 30, 40or 45 parts by weight or more with respect to 100 parts by weight of theresin component. The upper limit of the ratio of the moisture scavengerin the first layer may be changed according to a desired moistureblocking property, and the first layer may include a moisture scavengerat 250, 230 or 210 parts by weight or less with respect to the resincomponent, but the present invention is not particularly limitedthereto. The second layer may not include the moisture scavenger, orotherwise may include a trace amount of the moisture scavenger. Thesecond layer may include the moisture scavenger, for example, at lessthan 5 or 3 parts by weight with respect to 100 parts by weight of asolid content of the second layer. Since the second layer may notinclude a moisture scavenger, the lower limit of the content of themoisture scavenger in the second layer may be 0 parts by weight. Unlessparticularly defined otherwise, the unit “parts by weight” used hereinrefers to a weight ratio.

Thicknesses of the first and second layers may be controlled inconsideration of the number of layers included in the film or a use ofthe film. For example, when the film includes one of each of the firstand second layers, the thickness of the first layer may be approximately5 to 100 μm, and the thickness of the second layer may be approximately2 to 30 μm. In this range, the film having excellent moisture blockingproperty, workability and durability may be provided.

In one example, the first layer may include a resin component having acontact angle of 80, 85, 90 or 95 degrees or more with respect todeionized water. The contact angle is a contact angle measured after alayer is formed by coating a glass with a solution containingapproximately 15 wt % of a solid content prepared by dissolving theresin component in a suitable solvent and drying the coated solution,and deionized water is dropped onto the coating layer at approximately25° C., and may be an average of contact angles measured by repeatingthe above process 10 times. As the component whose contact angle iscontrolled as described above is included in the first layer, the filmhaving excellent moisture blocking property and durability may beprovided. The upper limit of the contact angle of the resin componentmay be, but is not particularly limited to, for example, 150 or 120degrees or less.

The first layer may also include a resin component having a WVTR of 50or 45 g/m²·day or less. The WVTR may be measured in a thicknessdirection of the film which is formed from the resin component to have athickness of 100 μm at 100° F. and a relative humidity of 100%. As theWVTR of the resin component is controlled as described above, the filmhaving an excellent moisture blocking property may be provided. As theWVTR of the first layer is lower, the film may have a better moistureblocking property, and thus the lower limit thereof is not particularlylimited. For example, the lower limit of the WVTR of the resin componentmay be 0 g/m²·day.

In one example, the resin component included in the first layer maysatisfy all of the above ranges of the contact angle and WVTR. As thefirst layer includes the component having the above ranges of thecontact angle and WVTR, the film having excellent moisture blockingproperty and water repellency may be provided.

As the resin component, any one of known components in the related artproviding a first layer satisfying the above-mentioned contact angle andWVTR or the above-mentioned elastic modulus can be used withoutparticular limitation. In addition, if a resin does not satisfy thecontact angle and WVTR alone, but satisfies the contact angle and WVTRin combination with another resin, the combined resin may be used as theresin component. The term “resin component” used herein may refer to abase resin forming the first layer. The base resin refers to a resinused to realize main physical properties of the first layer, excludingan optional component such as an additive. In one example, when anadditive such as a tackifier is added to the first layer, the base resinmay exclude a tackifier.

The component may be a styrene-based resin, a polyolefin-based resin, athermoplastic elastomer, a polyoxyalkylene-based resin, apolyester-based resin, a polyvinyl chloride-based resin, apolycarbonate-based resin, a polyphenylenesulfide-based resin, a mixtureof hydrocarbons, a polyamide-based resin, an acrylate-based resin, anepoxy-based resin, a silicon-based resin, a fluorine-based resin or amixture thereof.

Here, the styrene-based resin may be, for example, astyrene-ethylene-butadiene-styrene block copolymer (SEBS), astyrene-isoprene-styrene block copolymer (SIS), anacrylonitrile-butadiene-styrene block copolymer (ABS), anacrylonitrile-styrene-acrylate block copolymer (ASA), astyrene-butadiene-styrene block copolymer (SBS), a styrene-basedhomopolymer or a mixture thereof. The olefin-based resin may be, forexample, a high-density polyethylene-based resin, a low-densitypolyethylene-based resin, a polypropylene-based resin or a mixturethereof. The thermoplastic elastomer may be, for example, an ester-basedthermoplastic elastomer, an olefin-based thermoplastic elastomer or amixture thereof. Among these, the olefin-based thermoplastic elastomermay be a polybutadiene resin or a polyisobutene resin. Thepolyoxyalkylene-based resin may be, for example, apolyoxymethylene-based resin, a polyoxyethylene-based resin or a mixturethereof. The polyester-based resin may be, for example, a polyethyleneterephthalate-based resin, a polybutylene terephthalate-based resin or amixture thereof. The polyvinylchloride-based resin may be, for example,a polyvinylidene chloride. The mixture of hydrocarbons may be, forexample, hexatriacotane or paraffin. The polyamide-based resin may be,for example, nylon. The acrylate-based resin may be, for example, apolybutyl(meth)acrylate. The epoxy-based resin may be, for example, abisphenol type such as a bisphenol A-, bisphenol F-, or bisphenol S-typeepoxy-based resin or a hydrogenated product thereof; a novolac type suchas a phenolnovolac- or cresolnovolac-type epoxy-based resin; anitrogen-containing cyclic type such as a cyclictriglycidylisocyanurate- or hydantoin-type epoxy-based resin; analicyclic type; an aliphatic type; an aromatic type such as anaphthalene-type epoxy-based resin or a biphenyl-type epoxy-based resin;a glycidyl type such as a glycidylether-type epoxy-based resin, aglycidylamine-type epoxy-based resin, or a glycidylester-typeepoxy-based resin; a dicyclo type such as dicyclopentadiene-typeepoxy-based resin; an ester type; an etherester type; or a mixturethereof. The silicon-based resin may be, for example, apolydimethylsiloxane. In addition, the fluorine-based resin may be apolytrifluoroethylene resin, a polytetrafluoroethylene resin, apolychlorotrifluoroethylene resin, a polyhexafluoropropylene resin, apolyvinylidene fluoride, a polyvinyl fluoride, a polyethylene propylenefluoride or a mixture thereof.

The resin may be grafted with maleic acid anhydride, copolymerized withanother resin listed above or a monomer for preparing a resin, ormodified by another compound, which may be a carboxyl-terminal endbutadiene-acrylonitrile copolymer.

In addition, the listed resin may include at least one heat-curablefunctional group or site such as a glycidyl, isocyanate, hydroxyl,carboxyl or amide group, or at least one active energy ray-curablefunctional group or site such as an epoxide, cyclic ether, sulfide,acetal or lactone group to exhibit an adhesive property after curing.

In one example, the first layer may include a polyisobutene resin. Thepolyisobutene resin may exhibit low WVTR and surface energy due tohydrophobicity. Particularly, the polyisobutene resin may be, forexample, a homopolymer of an isobutylene monomer; or a copolymerprepared by copolymerizing another monomer which can be polymerized withan isobutylene monomer. Here, the monomer which can be polymerized withan isobutylene monomer may be, for example, 1-butene, 2-butene, isopreneor butadiene.

The resin component may be a resin having a weight average molecularweight (Mw) at which it can be molded in a film type. In one example,the range of the weight average molecular weight at which molding in afilm type is possible may be approximately 100,000 to 2,000,000, 100,000to 1,500,000 or 100,000 to 1,000,000. The term “weight average molecularweight (Mw)” used herein refers to a conversion value with respect to astandard polystyrene measured by gel permeation chromatography (GPC).

In addition, as the resin component, one or at least two of the aboveresins may be used. When at least two resins are used, the resins may bedifferent in kind, weight average molecular weight or both.

The first layer may further include a moisture scavenger in addition tothe resin component. Thus, the moisture blocking property of the firstlayer may be more enhanced.

In one example, the moisture scavenger may be present in a uniformlydispersed state in the resin component. Here, the uniformly dispersedstate may refer to a state in which the moisture scavenger is present atthe same or substantially the same density in any part of the resincomponent. The moisture scavenger capable of being used herein may be,for example, a metal oxide, a sulphate or an organic metal oxide.Particularly, the metal oxide may be magnesium oxide, calcium oxide,strontium oxide, barium oxide or aluminum oxide, the sulphate may bemagnesium sulphate, sodium sulphate or nickel sulphate, and the organicmetal oxide may be aluminum oxide octylate. The moisture scavenger whichmay be included in the first layer may use one or at least two of theabove materials. In one example, when at least two materials are usedfor the moisture scavenger, calcined dolomite may be used.

Such a moisture scavenger may be controlled in a suitable size accordingto a use of the film. In one example, an average particle diameter ofthe moisture scavenger may be controlled to approximately 10 to 15,000nm. Since a response rate with moisture is not excessively high, themoisture scavenger having a size within the above range may be easilystored, may not damage a diode to be encapsulated, and may effectivelyremove moisture.

A content of the moisture scavenger may be controlled to, for example, 5to 250 parts by weight with respect to 100 parts by weight of the resincomponent as described above.

In addition, in one example, the first layer may further include adispersing agent such that the moisture scavenger is uniformly dispersedin the resin component. As the dispersing agent capable of being usedherein, a non-ionic surfactant having an affinity to a hydrophilicsurface of the moisture scavenger and a compatibility with the resincomponent may be used. In one example, as the non-ionic surfactant, acompound represented by Formula 1 may be used.

R—X  [Formula 1]

In Formula 1, R is a saturated or unsaturated hydrocarbon group, and Xis a hydroxyl group, a carboxyl group, an amino group or a carbohydrateresidue.

In Formula 1, R may be a saturated or unsaturated hydrocarbon grouphaving 4 to 28, 4 to 24, 4 to 20 or 6 to 20 carbon atoms.

In addition, the compound of Formula 1 in which X is a carbohydrateresidue may refer to a compound in which one of hydrogen atoms in thecarbohydrate is substituted with R. The carbohydrate may be, forexample, glucose.

The compound of Formula 1 may be, for example, a fatty acid such asstearic acid, palmitic acid, oleic acid or linoleic acid; a fattyalcohol such as cetyl alcohol, stearyl alcohol, cetostearyl alcohol oroleyl alcohol; or an alkyl glucoside such as octyl glucoside, decylglucoside or lauryl glucoside.

A content of the dispersing agent may be controlled according to thekind and/or size of a moisture scavenger. Particularly, as the size ofthe moisture scavenger is decreased, a surface area of the moisturescavenger is increased, and thus a large amount of the dispersing agentis needed to uniformly disperse the moisture scavenger. In one example,when a moisture scavenger having an average particle diameter ofapproximately 40 nm is used, approximately 5 parts by weight of thedispersing agent may be used based on 100 parts by weight of themoisture scavenger. In one example, when a moisture scavenger having anaverage particle diameter of approximately 1,000 nm is used,approximately 0.05 parts by weight of the dispersing agent may be usedbased on 100 parts by weight of the moisture scavenger. Accordingly, inconsideration of the above-described kind and/or size of the moisturescavenger, approximately 0.01 to 500 parts by weight of the dispersingagent may be used based on 100 parts by weight of the moisturescavenger. In this range, the moisture scavenger may be uniformlydispersed with no influence on any physical properties including anadhesive strength of the film.

A method of including the moisture scavenger and the dispersing agent inthe first layer may be any method used in the related art withoutparticular limitation, and may be a method capable of uniformlydispersing the moisture scavenger in the resin component by controllinga mixing sequence. First, a dispersing solution is prepared bydispersing the dispersing agent in a solvent. Here, the solvent may beselected based on coatability, drying temperature or compatibility withthe resin component. In one example, when the polyisobutene resin isused as the resin component, an aromatic solvent such as toluene orxylene may be used as a solvent. The moisture scavenger is added to andmixed with the dispersing solution. Here, as the process of mixing themoisture scavenger with the dispersing solution, a physical dispersionmethod may further be used to increase dispersity of the moisturescavenger. The physical dispersion method may be, for example, a methodusing a shaker, sonication or bead milling. A composition for formingthe first layer may be obtained by adding the solution in which themoisture scavenger and the dispersing agent are dispersed to a solutionincluding the resin component. The solution in which the moisturescavenger and the dispersing agent are dispersed may be optionallyfiltered to screen large-sized particles, and then the filtered solutionmay be added to the solution including the resin component. Through theabove process, the first layer in which the moisture scavenger and thedispersing agent are uniformly dispersed in the resin component may beformed. However, the process is not limited to that described above, andwill be simply modified by one of ordinary skill in the art.

The first layer may further include a moisture blocker. The term“moisture blocker” used herein may refer to a material having no or lowreactivity to moisture penetrating the film, but capable of preventingor interrupting migration of moisture or vapor into the film. As themoisture blocker, one or at least two of clay, talc, needle-shapedsilica, planar silica, porous silica, zeolite, titania or zirconia maybe used. In addition, the moisture blocker may be surface-treated by anorganic modifier to facilitate penetration of an organic material. Theorganic modifier may be, for example, dimethyl benzyl hydrogenatedtallow quaternary ammonium, dimethyl dihydrogenated tallow quaternaryammonium, methyl tallow bis-2-hydroxyethyl quaternary ammonium, dimethylhydrogenated tallow 2-ethylhexyl quaternary ammonium, dimethyldehydrogenated tallow quaternary ammonium or a mixture thereof.

A content of the moisture blocker that may be included in the firstlayer may be suitably controlled in the relationship with a matrixstructure of the moisture scavenger and the resin component. In oneexample, the content of the moisture blocker may be controlled to 0 to50 parts by weight or 1 to 30 parts by weight with related to 100 partsby weight of the resin component. In this range, the film havingexcellent moisture blocking property and mechanical properties may beprovided.

In one example, the moisture scavenger and the moisture blocker may beuniformly dispersed in the resin component by controlling the mixingsequence of the component for the first layer even when the first layerincludes both the moisture scavenger and the moisture blocker.

For example, first, a first dispersing solution may be prepared byadding the moisture blocker to a solvent. Here, the first dispersingsolution may be obtained in a dispersing solution in which the moistureblocker is uniformly dispersed through a process such as sonication,bead milling, ball milling, high-speed dispersion or high-pressuredispersion. Separately, as described above, a second dispersing solutionin which the moisture scavenger and/or dispersing agent is (are)dispersed is prepared. The prepared first and second dispersingsolutions are added to and mixed with the solution including the resincomponent. During mixing, in consideration of the control in viscosityand coatability of the resin composition, a solvent may further beadded. According to the method described above, the first layer in whichthe moisture scavenger and the blocker are uniformly dispersed may beformed. The method of forming the first layer can be changed with regardto aspects well known to one of ordinary skill in the art withoutlimitation.

The first layer may further include a tackifier. As the tackifier, forexample, a hydrogenated petroleum resin obtained by hydrogenating apetroleum resin may be used. The hydrogenated petroleum resin may be apartially or completely hydrogenated resin, or a mixture of such resins.As the tackifier, one having a good compatibility with the resincomponent and an excellent moisture blocking property may be selected. Aparticular example of the hydrogenated petroleum resin may be ahydrogenated terpene-based resin, a hydrogenated ester-based resin or ahydrogenated dicyclopentadiene-based resin. The tackifer may have aweight average molecular weight of approximately 200 to 5,000. A contentof the tackifier may be suitably controlled when necessary. For example,the tackifier may be included in the first layer at 5 to 100 parts byweight with respect to 100 parts by weight of the resin component.

In addition to the components, various additives may be included in thefirst layer according to a use of the film and a process of forming thefilm. For example, in consideration of durability and processibility, acurable material may further be included in the first layer. Here, thecurable material may refer to a material having a heat-curablefunctional group and/or active energy ray-curable functional group whichare (is) included, in addition to the resin component. In addition, acontent of the curable material included in the first layer may becontrolled according to a desired physical property of the film.

For example, the second layer may be a layer including a curable resincomposition. The second layer may be a hot melt-type adhesive layer. Theterm “hot melt-type adhesive layer” used herein may refer to a layerwhich may maintain a solid or semi-solid state at room temperature, maybe melted when suitable heat is applied, thereby exhibiting apressure-sensitive adhesive property, and may firmly fix a targetmaterial as an adhesive after curing. In addition, the term “curing ofthe adhesive” used herein may refer to a chemical or physical action orreaction changing the target material to have an adhesive property. Inaddition, the term “room temperature” may refer to a temperature in anatural state, which is not increased or decreased, for example,approximately 15 to 35° C., 20 to 25° C., 25° C. or 23° C. In addition,here, the maintenance of a solid or semi-solid state at room temperaturemay refer to the target material having a viscosity of approximately 10⁶or 10⁷ poises or more at room temperature. Here, the viscosity ismeasured using an advanced rheometric expansion system (ARES). Here, theupper limit of the viscosity may be, but is not particularly limited to,for example, approximately 10⁹ poises or less.

For example, the second layer may maintain a solid or semi-solid stateat room temperature even in a state in which a component included in thesecond layer such as a curable resin composition is uncured.Accordingly, the second layer may include the curable resin compositionin a film type. As a result, excellent handleability may be obtained,physical or chemical damage to a diode during encapsulation may beprevented, and smooth working may progress.

The curable resin composition may be, for example, a curable resin. Asthe curable resin, a heat-curable, active energy ray-curable orhybrid-curable resin known in the related art may be used. Herein, theterm “heat-curable resin” may refer to a resin which may be curedthrough application of suitable heat or aging, the term “active energyray-curable resin” may refer to a resin which may be cured by radiationof an active energy ray, and the term “hybrid-curable resin” may referto a resin which may be cured by simultaneously or sequentiallyperforming curing mechanisms for a heat-curable and active energyray-curable resins. In addition, the active energy ray may bemicrowaves, an IR, UV or X ray, a gamma ray, or a particle beam such asan alpha-particle beam, proton beam, neutron beam or electron beam.

The curable resin is a resin exhibiting an adhesive property aftercuring, and may include at least one heat-curable functional group orsite such as a glycidyl, isocyanate, hydroxyl, carboxyl or amide group,or at least one active energy ray-curable functional group or site suchas an epoxide, cyclic ether, sulfide, acetal or lactone group. Thecurable resin may be, but is not limited to, an acrylic resin, polyesterresin, isocyanate resin or epoxy resin having the at least onefunctional group or site described above.

In one example, the curable resin may be an epoxy resin. The epoxy resinmay be an aromatic or aliphatic epoxy resin. As the epoxy resin, aheat-curable epoxy resin, or an active energy ray-curable epoxy resin,which is cured by cationic polymerization by radiation of an activeenergy ray, may be used.

The epoxy resin according to one example may have an epoxy equivalent of150 to 2,000 g/eq. In the range of the epoxy equivalent, acharacteristic such as adhesive performance or a glass transitiontemperature of a cured product may be maintained in an appropriaterange.

In one example, the epoxy resin may be an aromatic epoxy resin. The term“aromatic epoxy resin” used herein may refer to an epoxy resin includingan aromatic core such as a phenylene structure or an aromatic group suchas a phenyl group in a main or side chain of the resin. When thearomatic epoxy resin is used, the cured product has excellent thermaland chemical stabilities and a low WVTR, and thus reliability of theencapsulating structure for an electronic diode may be enhanced. Thearomatic epoxy resin may be, but is not limited to, one or at least twoof a biphenyl-type epoxy resin, a naphthalene-type epoxy resin, adicyclopentadiene-type epoxy resin, a dicyclopentadiene-modifiedphenol-type epoxy resin, a cresol-based epoxy resin, a bisphenol-basedepoxy resin, a xylok-based epoxy resin, a multifunctional epoxy resin, aphenol novolac epoxy resin, a triphenolmethane-type epoxy resin and analkyl-modified triphenolmethane epoxy resin. In one example, the epoxyresin may be a silane-modified epoxy resin. The silane-modified epoxyresin may be, for example, a reaction product between at least one ofthe epoxy resins described above and a silane compound. Here, the silanecompound may be, for example, a compound represented by Formula 2.

D_(n)SiQ_((4-n))  [Formula 2]

In Formula 2, D is a vinyl group, an epoxy group, an amino group, anacryl group, a methacryl group, a mercapto group, an alkoxy group or anisocyanate group, or an alkyl group substituted with at least one of thefunctional groups, Q is hydrogen, an alkyl group, a halogen, an alkoxygroup, an aryl group, an aryloxy group, an acyloxy group, an alkylthiogroup or an alkyleneoxythio group, and n is a number between 1 and 3.

In the compound of Formula 2, the functional group D may form asilane-modified epoxy resin by a reaction with a functional groupincluded in the epoxy resin.

For example, when the functional group is an amino group, the aminogroup may form a bond “—CH(OH)—CH₂—NH—” by a reaction with an epoxygroup of the epoxy resin, and thus the silane compound may be introducedinto the epoxy group.

In addition, when the functional group D is an isocyanate or alkoxygroup, a silane compound may be introduced by a reaction with an epoxyresin including a hydroxyl (OH) group, for example, a bisphenol-typeepoxy resin such as a bisphenol F-type epoxy resin, a bisphenol F-typenovolac epoxy resin, a bisphenol A-type epoxy resin or a bisphenolA-type novolac epoxy resin.

In Formula 2, the alkyl group may be an alkyl group having 1 to 20, 1 to16, 1 to 12, 1 to 8 or 1 to 4 carbon atoms. The alkyl group may be alinear, branched or cyclic alkyl group.

In Formula 2, a halogen atom may be fluorine (F), chlorine (Cl), bromine(Br) or iodine (I).

In addition, in Formula 2, the alkoxy group may be an alkoxy grouphaving 1 to 20, 1 to 12, 1 to 8 or 1 to 4 carbon atoms. The alkoxy groupmay be a linear, branched or cyclic alkoxy group.

In addition, in Formula 2, the aryl group or aryl group included in thearyloxy group may be an aryl group or an aralkyl group. For example, thearyl group may refer to a monovalent residue derived from a compoundincluding at least one benzene ring or a structure in which at least twobenzene rings are linked or condensed or a derivative thereof. The arylgroup may be, for example, an aryl group having 6 to 25, 6 to 21, 6 to18 or 6 to 12 carbon atoms. As the aryl group, for example, a phenylgroup, a dichlorophenyl group, a chlorophenyl group, a phenylethylgroup, a phenylpropyl group, a benzyl group, a tolyl group, a xylylgroup or a naphthyl group may be used.

In addition, in Formula 2, the acyloxy group may be an acyloxy grouphaving 1 to 20, 1 to 16 or 1 to 12 carbon atoms.

In addition, in Formula 2, the alkylthio group may be an alkylthio grouphaving 1 to 20, 1 to 16, 1 to 12, 1 to 8 or 1 to 4 carbon atoms, thealkyleneoxythio group may be an alkyleneoxythio group having 1 to 20, 1to 16, 1 to 12, 1 to 8 or 1 to 4 carbon atoms.

The alkyl, alkoxy, aryl, acyloxy, alkylthio or alkyleneoxythio group maybe optionally substituted with at least one substituent. The substituentmay be, but is not limited to, a hydroxyl group, an epoxy group, analkyl group, an alkenyl group, an alkynyl group, an alkoxy group, anacyl group, a thiol group, an acryloyl group, a methacryloyl group, anaryl group or an isocyanate group.

In Formula 2, the functional group D may be, for example, an alkoxygroup, an amino group or an isocyanate group among these.

In addition, in Formula 2, at least one, two or three of the functionalgroups Q may be, for example, a halogen atom, an alkoxy group, anaryloxy group, an acyloxy group, an alkylthio group or analkyleneoxythio group, or an alkoxy group.

As the silane-modified epoxy group, for example, an epoxy resin intowhich a silane compound is introduced at approximately 0.1 to 10 partsby weight, 0.1 to 9 parts by weight, 0.1 to 8 parts by weight, 0.1 to 7parts by weight, 0.1 to 6 parts by weight, 0.1 to 5 parts by weight, 0.1to 4 parts by weight, 0.1 to 3 parts by weight, 0.3 to 2 parts by weightor 0.5 to 2 parts by weight with respect to 100 parts by weight of theepoxy resin. In one example, the epoxy resin to which the silanecompound is introduced may be an aromatic epoxy resin. The aromaticepoxy resin may be, for example, a bisphenol-type epoxy resin such as abisphenol F-type epoxy resin, a bisphenol F-type novolac epoxy resin, abisphenol A-type epoxy resin or a bisphenol A-type novolac epoxy resin.

Due to the epoxy resin which is modified by a silane to include a silylgroup in its structure, the encapsulating layer of an electronic devicemay have an excellent adhesive property to a substrate, etc., andexcellent moisture blocking property, durability and reliability.

The second layer may further include a curing agent which may form acrosslinking structure by a reaction with a curable resin or aninitiator which may initiate a curing reaction of the resin depending onthe kind of the curable resin.

A suitable kind of the curing agent may be selected and used accordingto the kind of the curable resin or a functional group included in theresin.

In one example, when the curable resin is an epoxy resin, as a curingagent, a curing agent for the epoxy resin known in the related art maybe used, and may be, but is not limited to, one or at least two of anamine curing agent, an imidazole curing agent, a phenol curing agent, aphosphorus curing agent or an acid anhydride curing agent.

In one example, as the curing agent, an imidazole compound which issolid at room temperature and has a melting point or decompositiontemperature of 80° C. or more may be used. Such a compound may be, butis not limited to, 2-methyl imidazole, 2-heptadecyl imidazole, 2-phenylimidazole, 2-phenyl-4-methyl imidazole or 1-cyanoethyl-2-phenylimidazole.

A content of the curing agent may be selected according to a compositionof the composition, for example, a kind or ratio of the curable resin.For example, the curing agent may be included at 1 to 20, 1 to 10 or 1to 5 parts by weight with respect to 100 parts by weight of the curableresin. However, the weight ratio may be changed according to the kindand ratio of a curable resin or a functional group of the resin, or acrosslinking density to be realized.

When the curable resin is an epoxy resin which may be cured by radiationof an active energy ray, as an initiator, for example, a cationicphotoinitiator may be used.

The cationic photoinitiator may be an onium salt or organometallicsalt-based ionized cationic initiator or an organic silane or latentsulfonic acid-based non-ionized cationic photoinitiator. The oniumsalt-based initiator may be a diaryliodonium salt, a triarylsulfoniumsalt or an aryldiazonium salt, the organic metal salt-based initiatormay be an iron arene, the organic silane-based initiator may be ano-nitrobenzyl triaryl silyl ether, a triaryl silyl peroxide or an acylsilane, and the latent sulfonic acid-based initiator may beα-sulfonyloxy ketone or α-hydroxymethylbenzoin sulfonate, but thepresent invention is not limited thereto.

In one example, the cationic initiator may be an ionized cationicphotoinitiator.

A content of the initiator may be changed according to the kind andratio of a curable resin or a functional group of the resin, or acrosslinking density to be realized like the curing agent. For example,the initiator may be blended at a content of 0.01 to 10 parts by weightor 0.1 to 3 parts by weight with respect to 100 parts by weight of thecurable resin. When the content of the curing agent is excessivelysmall, curing may not be sufficiently performed, and when the content ofthe curing agent is excessively high, a content of an ionic material isincreased after curing, and thus the durability of the adhesive isdegraded or a conjugate acid is formed due to the characteristic of theinitiator, which is inappropriate for optical durability. In addition,depending on a base, corrosion may occur, and therefore a suitablecontent range may be selected.

The second layer may further include a binder resin. The binder resinmay serve to improve moldability when molded in a film or sheet type.

The kind of a binder resin is not particularly limited if a resin has acompatibility with a different resin such as a curable resin. The binderresin may be a phenoxy resin, an acrylate resin or a high molecularweight epoxy resin. Here, the high molecular weight epoxy resin mayrefer to a resin having a weight average molecular weight ofapproximately 2,000 to 70,000 or 4,000 or 6,000. The high molecularweight epoxy resin may be a solid bisphenol A-type epoxy resin or asolid bisphenol F-type epoxy resin. As the binder resin, a rubbercomponent such as a high-polarity functional group-containing rubber ora high-polarity functional group-containing reactive rubber may be used.In one example, the binder resin may be a phenoxy resin.

When the binder resin is included, its ratio may be controlled accordingto a desired physical property, but is not particularly limited. Forexample, the binder resin may be included at a content of approximately200, 150 or 100 parts by weight with respect to 100 parts by weight of acurable adhesive component. When the content of the binder resin is 200parts by weight or less, a compatibility with each component of thesecond layer may be effectively maintained, and the binder resin mayserve as an adhesive layer.

The second layer may further include a moisture blocker. When themoisture scavenger is in contact with a diode including an organicmaterial, it may damage the diode by a chemical reaction with moisture.Accordingly, the second layer may or may not include a trace amount ofthe moisture scavenger. When the second layer includes a trace amount ofthe moisture scavenger, a content of the moisture scavenger may be asdescribed above. However, the moisture blocker makes a migration pathfor moisture longer to block moisture, and since it has a smallerreactivity than the moisture scavenger, it has a lower chance ofdamaging the diode. A content of the moisture blocker which may beincluded in the second layer may be, for example, approximately 0.01 to50 parts by weight or 1 to 30 parts by weight based on 100 parts byweight of the curable resin. A particular kind of the moisture blockerand a method of dispersing the moisture blocker in the curable resin maybe understood with reference to the moisture blocker included in thefirst layer and the method of including the moisture blocker.

The second layer may further include an additive such as a plasticizingagent, a UV stabilizer and/or an antioxidant without affecting a desiredeffect.

The film may further include a base. The base may be disposed on one orboth surfaces of the film. The base may be, for example, arelease-treated base, or any one used in the related art withoutlimitation.

The encapsulating film may encapsulate and protect various targets.Particularly, the film may be effective in protecting a target includinga diode sensitive to an external component, for example, moisture orvapor. As an example of the target to which the encapsulating film maybe applied, an organic electronic device such as a photovoltaic device,a rectifier, a transmitter or an OLED, a solar cell or a secondarybattery may be used, but the present invention is not limited thereto.

Another aspect of the present invention provides an electronic deviceincluding an upper substrate, a bottom substrate, and an encapsulatinglayer including a film encapsulating a diode between the upper substrateand the bottom substrate. Here, the diode may refer to any one part ofthe electronic device. As a representative example of the diode whichmay be protected by the film, an organic electronic diode such as anOLED may be used, but the present invention is not limited thereto.

In one example, the film may be the encapsulating film having first andsecond layers described above. The film may be, for example, uncured.The encapsulating layer including the above film may be a layer formedby curing the film.

In the electronic device, the upper substrate may be disposed to facethe bottom substrate. In addition, the diode may be formed on onesurface of the bottom substrate, which may face the upper substrate. Thefilm may be disposed between the upper and bottom substrates, and thesecond layer of the film may be disposed to be in contact with thebottom substrate having the diode. In such a structure, the film maysubstantially cover an entire surface of the diode. In one example, asshown in FIG. 3, the film 24 may include a first layer 12 and a secondlayer 11, and the second layer 11 may be disposed to be in contact witha diode 23 and a bottom substrate 22. In addition, in another example,as shown in FIG. 4, the film 24 may include a second layer 11, a firstlayer 12 and another second layer 11, and any one of the second layers11 may be disposed to be in contact with a diode 23 and a bottomsubstrate 22. As described above, since the second layer includes atrace amount of or no moisture scavenger capable of damaging the diode,it does not influence a function even when the second layer is incontact with the diode. In addition, as described above, the secondlayer has a step difference compensating property, and thus may beattached to a surface having a height difference such as the bottomsubstrate having the diode 23 without lifting and/or bubbles. As aresult, the electronic device having an excellent interface adhesivestrength between the encapsulating layer and the diode or bottomsubstrate may be provided.

In the encapsulating layer formed by curing the film, the second layermay have a glass transition temperature of 0, 50, 70, 85 or 100° C. ormore. Since the first layer may include large amounts of the moisturescavenger, ions generated by a reaction between the moisture scavengerand moisture may migrate to the second layer. However, the second layermay be in contact with the diode, and thus the ions migrating from thefirst layer to the second layer may influence performance of the diode.For this reason, the second layer may be sufficiently cured, therebypreventing the migration of the ions from the first layer to the secondlayer, and deterioration of the performance of the diode. That is, thesecond layer may have the above-described effects by preventing themigration of the ions having a glass transition temperature within inthe above range from the first layer to the second layer.

In one example, the electronic device may be an organic electronicdevice. The encapsulating layer may exhibit excellent moisture blockingproperty and optical properties in the organic electronic device, andeffectively fix and support the upper substrate and the bottomsubstrate. In addition, the encapsulating layer may have excellenttransparency since the moisture scavenger is prepared in a nano size anduniformly dispersed in the resin, and thus become stable regardless of ashape of the organic electronic device such as a top emission or bottomemission type.

The organic electronic device may be provided in a conventionalconfiguration known in the related art except that the encapsulatinglayer is formed of the above film. For example, as the bottom or uppersubstrate, a glass, metal or polymer film, which is conventionally usedin the related art, may be used. In addition, the OLED may include, forexample, a pair of electrodes and a layer of an organic material formedbetween the pair of electrodes. Here, any one of the pair of electrodesmay be a transparent electrode. In addition, the layer of an organicmaterial may include, for example, a hole transport layer, an emittinglayer and an electron transport layer.

Still another aspect of the present invention provides a method ofmanufacturing an electronic device including laminating theabove-described film on a substrate on which a diode is formed such thata second layer of the film is in contact with the diode.

In one example, the method of manufacturing an electronic device may bea method of manufacturing the above-described electronic device.

In the above, to stack the film to be in contact with the diode, thefilm may be applied to cover an entire surface of the diode.

In addition, the laminating of the second layer of the film to be incontact with the diode may include disposing the second layer of thefilm to be in contact with the diode, and pressing the diode while thesecond layer is heated to provide flowability. In one example, thesecond layer may be solid or semi-solid at room temperature, and may beheated to maintain a viscosity of 10³ to 10⁵ Pa·s at 65° C. and 1 Hzwhen the second layer is in contact with the diode. When the secondlayer is the above-described hot melt-type adhesive layer, it may beattached to a surface having a height difference such as the substrateon which the diode is formed without lifting and/or bubbles.Accordingly, even a large-scale electronic device may be providedwithout degradation in performance due to bubbles.

Here, when the second layer includes a heat-curable resin, the heatingmay be controlled to a temperature within approximately 40 to 100° C.and a time within 1 to 20 minutes since a cohesive strength and anadhesive strength of the encapsulating layer may be decreased due toovercuring.

In addition, the pressing may be performed using a vacuum press toprevent bubbles from being generated between the diode and the secondlayer.

In addition, the method may include curing the second layer after thesecond layer is stacked to be in contact with the diode. The curingprocess may be performed in a suitable heating chamber or UV chamberdepending on, for example, a method of curing a curable resin. Heatingconditions or conditions for radiating an active energy ray may besuitably selected in consideration of stability of the electronic diodeand curability of a curable resin composition.

In one example, the curing may be performed such that the second layerhas a glass transition temperature of 0° C., 50° C., 70° C., 85° C. or100° C. or more. When the curing is performed such that the second layerhas the above range of a glass transition temperature, it can preventthe migration of ions from the first layer to the second layer, and thusthe above-described effects can be exhibited.

In one example, the film may be pre-transferred to the upper substrateof the electronic device before laminating. As shown in FIG. 5, when thefilm 24 includes a first layer 12 and a second layer 11, the first layer12 of the film may be transferred to an upper substrate 21. In oneexample, when the first layer 12 has a pressure-sensitive adhesiveproperty, it may be attached to the upper substrate 21 by apredetermined pressure. Accordingly, the transfer of the first layer maybe performed by roll lamination after the first layer is in contact withthe upper substrate 21. In addition, in another example, when the firstlayer 12 has an adhesive property, the transfer of the first layer 12may be performed as described in the method of laminating the secondlayer, on a diode, and curing of the first layer 12 may be included.Afterward, as described above, the second layer 11 of the film may bestacked on the diode 23.

In addition, as shown in FIG. 6, when the film 24 includes a secondlayer 11, a first layer 12 and a second layer 11, the second layer 11 ofthe film may be transferred to an upper substrate 21. The transfer ofthe second layer 11 may be performed as described in the method oflaminating the second layer on the diode, and include curing the secondlayer.

The method described above is an example of the method of manufacturingan electronic device, but the present invention is not limited thereto.The process of manufacturing the device may be performed as describedabove, but a sequence or conditions of the process may be changed.

Effect

An encapsulating film having excellent moisture blocking property,handleability, workability and durability and a structure including adiode encapsulated with the encapsulating film can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a film according to an exemplaryembodiment;

FIG. 2 is a schematic diagram of a film according to another exemplaryembodiment;

FIG. 3 is a schematic diagram of an organic electronic device accordingto an exemplary embodiment;

FIG. 4 is a schematic diagram of an organic electronic device accordingto another exemplary embodiment;

FIG. 5 is a schematic diagram illustrating a method of manufacturing anorganic electronic device according to an exemplary embodiment; and

FIG. 6 is a schematic diagram illustrating a method of manufacturing anorganic electronic device according to another exemplary embodiment.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, a film will be described in further detail with referenceto Examples and Comparative Examples, but the scope of the film is notlimited to the following Examples.

Hereinafter, physical properties shown in Examples and ComparativeExamples are evaluated by the following methods.

1. Measurement of Tensile Modulus

A resin composition was prepared by dissolving a first or second layerprepared in Example or Comparative Example in a solvent. The resincomposition was coated on a base film (releasing polyester film, RS-21G,SKC) having a thickness of 38 μm. Subsequently, the coated compositionwas dried at 110° C. for 10 minutes, and thereby a film-type layerhaving a thickness of 40 μm was prepared. The prepared coating layer wasdesigned to be coated in a length direction, and then cut in a size of50 mm×10 mm (length×width), thereby preparing a specimen. Both terminalends of the specimen were taped to leave 25 mm in a length direction.Subsequently, while the taped part was extended at 25° C. at a rate of18 mm/min, a tensile modulus was measured.

2. Evaluation of Moisture Blocking Property

Calcium (Ca) was deposited on a glass substrate having a size of 12mm×12 mm (length×width) to have a size of 10 mm×10 mm (length×width).Separately, a film formed in Example or Comparative Example was cut to asize of 12 mm×12 mm (length×width). Subsequently, the first layer or onesurface of the film was transferred to a cover glass. Afterward, anopposite surface to that of the film on which the cover glass wasdisposed was laminated on the calcium of the glass substrate, andthermally pressed using a vacuum press at 80° C. for 2 minutes, andcured at 100° C. for 3 hours, thereby forming an encapsulating layer.Thus, a specimen was manufactured. Then, while the specimen wasmaintained in a constant temperature and constant humidity chamber at85° C. and a relative humidity of 85% for approximately 500 hours, alength of the calcium-deposited part which was oxidized and madetransparent was measured. Since calcium had a total length in onedirection of 10 mm, the length of the oxidized part of the calcium fromone terminal end became 5 mm, which meant that all of the calcium wasoxidized.

3. Evaluation of Durability and Reliability

A film formed in Example or Comparative Example was laminated betweensoda lime glass substrates, thermally pressed using a vacuum press at80° C. for 2 minutes, and curing the substrates at 100° C. for 3 hours,thereby forming an encapsulating layer. As a result, a specimen wasprepared. Afterward, while the specimen was maintained in a constanttemperature and constant humidity chamber at 85° C. and a relativehumidity of 85% for approximately 500 hours, it was observed whether ornot lifting occurred at an interface between the glass substrate and theencapsulating layer.

4. Evaluation of Applicability of Panel

A film formed in Example or Comparative Example was cut to a size of 90mm×90 mm (length×width), and a first layer or one surface of the filmwas transferred to a cover glass. Then, an opposite surface to that ofthe film on which the cover glass was disposed was thermally pressed ona glass substrate having a size of 100 mm×100 mm (length×width) using avacuum press at 80° C. for 2 minutes, and cured at 100° C. for 3 hours,thereby preparing a specimen. It was observed whether or not bubbleswere generated in the specimen.

Example 1 (1) Preparation of First Layer Solution

A moisture scavenger solution was prepared by adding 100 parts by weightof calcined dolomite as a moisture scavenger and 0.5 parts by weight ofstearic acid as a dispersing agent to a solution to have a solid contentof 50 wt %, and the solution was milled by ball milling for 24 hours. Inaddition, separately, 70 parts by weight of a polyisobutene resin(Product Name: B100, Manufacturer: BASF) having a weight averagemolecular weight of 1,100,000 was added to a reaction vessel as a resincomponent for the first layer, and 30 parts by weight of a hydrogenateddicyclopentadiene-based resin (Product Name: SU-90, Manufacturer: Kolon)was added as a tackifier and then diluted with toluene to have a solidcontent of approximately 20 wt %. Afterward, an inside of the reactionvessel was substituted with nitrogen, and the prepared solution washomogenized. The previously-prepared moisture scavenger solution wasadded to the homogenized solution to have a content of calcined dolomiteof 50 parts by weight with respect to 100 parts by weight of the resincomponent. Thus, a first layer solution was prepared.

(2) Preparation of Second Layer Solution

A second layer solution was prepared by adding 100 parts by weight of asilane-modified epoxy resin (KSR-177, Kukdo Chemical), 100 parts byweight of a bisphenol A-type epoxy resin (YD-011, Kukdo Chemical) and 80parts by weight of a phenoxy resin (YP-50, Tohto Kasei) to a reactionvessel at room temperature, diluting the resulting mixture withmethylethylketone, substituting an inside of the reaction vessel withnitrogen, homogenizing the prepared solution, adding 4 parts by weightof an imidazole (Shikoku Chemical) as a curing agent to the homogenizedsolution, and stirring the resulting solution at a high rate for 1 hour.

(3) Formation of Film

A first layer was formed to a thickness of 40 μm by coating the solutionof a first layer previously prepared on a release surface of releasingPET and drying the coated solution at 110° C. for 10 minutes.

A second layer was formed to a thickness of 15 μm by coating thesolution of a second layer previously prepared on a release surface ofreleasing PET and drying the coated solution at 130° C. for 3 minutes.

A multilayer film was formed by laminating the first and second layers.

Example 2

A first layer solution, a second layer solution and a film were preparedas described in Example 1, except that a moisture scavenger solution wasadded to have a content of calcined dolomite of 100 parts by weight withrespect to 100 parts by weight of the resin component.

Example 3

A first layer solution, a second layer solution and a film were preparedas described in Example 1, except that a moisture scavenger solution wasadded to have a content of calcined dolomite of 200 parts by weight withrespect to 100 parts by weight of the resin component.

Example 4 (1) Preparation of First Layer Solution

A first layer solution was prepared by adding 100 parts by weight of acarboxyl-terminal end butadiene-acrylonitrile (CTBN)-modified epoxyresin (Product Name: KR-207, Manufacturer: Kukdo Chemical) and 100 partsby weight of a phenoxy resin (YP-50, Tohto Kasei) as resin components toa reaction vessel at room temperature, diluting the resulting mixturewith toluene to have a solid content of approximately 20 wt %,homogenizing the prepared solution, putting 4 parts by weight of animidazole (Shikoku Chemical) into the homogenized solution as a curingagent, stirring the resulting solution at a high rate for 1 hour, andmixing the same moisture scavenger solution as prepared in Example 1with the resulting solution to have a content of calcined dolomite of 70parts by weight with respect to 100 parts by weight of the resincomponent.

(2) Preparation of Second Layer Solution

A second layer solution was prepared as described in Example 1.

(3) Formation of Film

A film was formed as described in Example 1, except that the solutionprepared in Example 4 was used as a first layer solution.

Example 5

A first layer solution, a second layer solution and a film were preparedas described in Example 4, except that 70 parts by weight of adicyclopentadiene-based epoxy resin (DCPD) and 30 parts by weight of amaleic acid anhydride-modified isobutene copolymer (Product Name:Glissopal, Manufacturer: BASF) were used as resin components for thefirst layer instead of 100 parts by weight of a CTBN-modified epoxyresin.

Comparative Example 1

A second layer solution and a film were prepared as described in Example1, except that the second layer solution in Example 1 was used as afirst layer solution. However, the first layer solution prepared byadding the same moisture scavenger solution as prepared in Example 1 tothe solution to have a content of calcined dolomite of 10 parts byweight with respect to 100 parts by weight of an epoxy resin was used.

Comparative Example 2

A first layer solution, a second layer solution and a film were preparedas described in Comparative Example 1, except that a moisture scavengersolution was added to have a content of calcined dolomite of 50 parts byweight with respect to 100 parts by weight of an epoxy resin.

Comparative Example 3

A first layer solution, a second layer solution and a film were preparedas described in Comparative Example 1, except that a moisture scavengersolution was added to have a content of calcined dolomite of 70 parts byweight with respect to 100 parts by weight of an epoxy resin.

Comparative Example 4

A first layer solution, a second layer solution and a film were preparedas described in Comparative Example 1, except that a moisture scavengersolution was added to have a content of calcined dolomite of 100 partsby weight with respect to 100 parts by weight of an epoxy resin.

Comparative Example 5 (1) Preparation of First Layer Solution

A first layer solution was prepared as described in Comparative Example3.

(2) Preparation of Second Layer Solution

A second layer solution was prepared by adding 70 parts by weight of apolyisobutene resin and 30 parts by weight of a hydrogenateddicyclopentadiene-based resin to a reaction vessel at room temperature,diluting the resulting mixture with toluene to have a solid content of20 wt %, substituting an inside of the reaction vessel with nitrogen,and homogenizing the prepared solution.

(3) Formation of Film

A film was formed as described in Comparative Example 3, except that thesecond layer solution prepared in Comparative Example 5 was used as asecond layer solution.

Comparative Example 6 (1) Preparation of First Layer Solution

A first layer solution was prepared as described in Example 1, exceptthat a moisture scavenger solution was added to have a content ofcalcined dolomite of 70 parts by weight with respect to 100 parts byweight of the resin component.

(2) Preparation of Second Layer Solution

98 parts by weight of n-butyl acrylate (n-BA), 2 parts by weight of2-hydroxyethyl acrylate and 100 parts by weight of ethyl acetate (EAc)as a solvent were added to a 1 L reaction vessel refluxing nitrogen gasand equipped with a cooling device to facilitate temperature control.Afterward, nitrogen gas purging was performed for 1 hour to removeoxygen, and a temperature was maintained at 60° C. 0.05 parts by weightof azobisisobutyronitrile (AIBN) and 0.01 parts by weight ofn-dodecylmercaptane were further added thereto as reaction initiators toreact. After the reaction, the reaction product was diluted with ethylacetate, thereby preparing an acryl resin solution having a weightaverage molecular weight of 1,300,000 and a solid content of 25 wt %. Atetrafunctional epoxy compound (Product Name: BXX5627, Manufacturer: TowInk Mfg. Co., Ltd) was mixed as an epoxy crosslinking agent with thesolution at 0.5 parts by weight with respect to 100 parts by weight of asolid content of an acryl resin solution. As a result, a second layersolution was prepared.

(3) Formation of Film

A film was formed as described in Example 1, except that the firstsolution prepared in Comparative Example 6 was used as a first layersolution, and the second layer solution prepared in Comparative Example6 was used as a second layer solution.

Comparative Example 7

A first layer solution and a film were prepared as described inComparative Example 6, except that the second layer solution prepared inComparative Example 5 was used as a second layer solution.

TABLE 1 Moisture Blocking Durability and Possibility to M1^(a) M2^(b)M1/M2 Property^(c) Reliability Apply Panel EXAMPLE 1 0.68 580 0.0012 2Good No Bubbles 2 0.68 580 0.0012 1.6 Good No Bubbles 3 0.68 580 0.00121.1 Good No Bubbles 4 120 580 0.0017 4.3 Good No Bubbles 5 98 580 0.16904.1 Good No Bubbles C. EXAMPLE 1 580 580 1 More than 5 Destroyed NoBubbles 2 580 580 1 More than 5 Destroyed No Bubbles 3 580 580 1 Morethan 5 Destroyed No Bubbles 4 580 580 1 More than 5 Destroyed No Bubbles5 580 0.68 853 More than 5 Destroyed Bubbles 6 0.68 0.45 1.5111 Morethan 5 Good Bubbles 7 0.68 0.68 1 More than 5 Good Bubbles ^(a)TensileModulus (Unit: MPa) of First Layer ^(b)Tensile Modulus (Unit: MPa) ofSecond Layer ^(c)Length of calcium oxidized in one direction from onesurface (Unit: mm) *C. EXAMPLE: Comparative Example

1. An encapsulating film, comprising: a first layer; and a second layerhaving a ratio (M1/M2) of the tensile modulus (M1) after curing at 25°C. of the first layer to the tensile modulus (M2) after curing at 25° C.of the second layer of 1×10⁻⁶ to 0.5.
 2. The film according to claim 1,wherein the tensile modulus after curing at 25° C. of the first layer is0.001 to 400 MPa.
 3. The film according to claim 1, wherein the tensilemodulus after curing at 25° C. of the second layer is 400 to 1000 MPa.4. The film according to claim 1, wherein the second layer is disposedon one or both surfaces of the first layer.
 5. The film according toclaim 1, wherein the first layer includes a resin component.
 6. The filmaccording to claim 5, wherein the first layer further includes amoisture scavenger.
 7. The film according to claim 6, wherein the firstlayer includes the moisture scavenger of 5 to 250 parts by weight withrespect to 100 parts by weight of the resin component.
 8. The filmaccording to claim 1, wherein the second layer includes the moisturescavenger at less than 5 parts by weight with respect to 100 parts byweight of a total solid content of the second layer.
 9. The filmaccording to claim 1, wherein the second layer is a solid or semi-solidat room temperature.
 10. The film according to claim 9, wherein thesecond layer is in a non-cured state.
 11. The film according to claim 1,wherein the second layer includes a curable resin composition.
 12. Thefilm according to claim 11, wherein the second layer includes thecurable resin composition in a film type.
 13. An electronic devicecomprising: an upper substrate; a bottom substrate; and an encapsulatinglayer which includes the film of claim 1 encapsulating a diode betweenthe upper and bottom substrates.
 14. The electronic device according toclaim 13, wherein the diode is formed on a surface of the bottomsubstrate facing the upper substrate, and the second layer of the filmis in contact with the bottom substrate.
 15. A method of manufacturingan electronic device, comprising: laminating the film of claim 1 on asubstrate on which a diode is formed such that the second layer of thefilm is in contact with the diode.